FIELD OF THE INVENTION
The invention relates to the treatment of waste materials, such as shredder waste (also called Shredderleichtraktion in German) or residues. This waste arises from the recycling of bulky metal scrap by fragmentising using, e.g. a hammer mill. The heavy metal scrap typically is automobile bodies, white goods, light iron, heavy steel, structural steel. The raw material is fed into the hammermill, initially shred, and cleaned magnetically and by eddy currents to produce ferrous and non-ferrous products on separate production lines.
About 75% of old cars are fed into shredder installations for recycling the materials. About 25% of the shredder charge remains as non-recoverable residues and is disposed of mainly in landfill sites. The shortage of landfill capacity has in recent years driven up the costs of properly disposing of these residues. This cost increase, together with the decline in profits, is increasingly resulting in a disposal crisis for the car recycling business. The difficult situation regarding disposal has already led to the closure of shredder plants. This results in a shortage for the steel industry of an important source of raw material for steel manufacture and like processes.
The shredder waste typically comprises metals, plastics, wood and rubber, and depending on the nature of the material being fragmented will also contain copper, aluminium and other elements derived from say stainless steel, and possibly silica.